/**
 * Copyright (c) 2008, Piercarlo Slavazza
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * The name of Piercarlo Slavazza cannot be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Piercarlo Slavazza ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL Piercarlo Slavazza BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.libapml;

import java.util.ArrayList;
import java.util.List;

import com.libapml.util.Helper;

public class Concept implements Closable {

	private String term;
	private List<ConceptOccurrenceInDocument> documentOccurrencies = new ArrayList<ConceptOccurrenceInDocument>();
	
	private double idf = -1;
	private double tfidfMean = -1;
	
	private boolean closed = false;
	
	protected Concept(String term) {
		this.term = term;
	}

	protected void add(ConceptOccurrenceInDocument documentOccurrence) {
		documentOccurrencies.add(documentOccurrence);
	}

	public String getTerm() {
		return term;
	}
	
	public List<ConceptOccurrenceInDocument> getDocumentOccurrencies() {
		return new ArrayList<ConceptOccurrenceInDocument>(documentOccurrencies);
	}
	
	public int getDocumentOccurrenciesCount() {
		return documentOccurrencies.size();
	}
	
	public int getTotalOccurrenciesCount() {
		
		int count = 0;
		
		for (ConceptOccurrenceInDocument documentOccurrence : documentOccurrencies)
			count += documentOccurrence.getOccurrencies();
		
		return count;
	}
	
	protected synchronized void close(int overallDocumentsCount) {
		
		if (!closed) {
			
			idf = Math.log((double)overallDocumentsCount / (double) getDocumentOccurrenciesCount());
			
			for (ConceptOccurrenceInDocument documentOccurrence : documentOccurrencies)
				documentOccurrence.close(idf);

			double tfidfTotal = 0.0;
			for (ConceptOccurrenceInDocument documentOccurrence : documentOccurrencies)
				tfidfTotal += documentOccurrence.getTfidf();
			
			tfidfMean = tfidfTotal / (double) overallDocumentsCount;
			
			closed = true;
		}
	}

	@Override
	public boolean equals(Object obj) {
		
		boolean areEquals = false;
		
		if (obj instanceof Concept)
			areEquals = term.equals(((Concept)obj).getTerm());
		
		return areEquals;
	}

	@Override
	public int hashCode() {
		return term.hashCode();
	}

	public synchronized double getTfidfMean() {
		
		Helper.checkIsClosed(this);
		
		return tfidfMean;
	}

	public synchronized boolean isClosed() {
		return closed;
	}
	
}
